Flyspeck prevention, Group A fungicides (strobilurins and Topsin M):  August-September spray dates

    Continuous protection from June 22 until 30 days before harvest is recommended.  Flyspeck infections that begin before August 15 are likely to become visible around September 20.  Infections that begin before August 25 are likely to become visible around October 20.  But warm wet weather in September can reduce flyspeck development time resulting in earlier dates of flyspeck appearance before harvest.
     Postinfection control of flyspeck may occur with application a strobilurin or Topsin M fungicide within 50 wet hours after the 'Protection end date' of the previous fungicide application.
Weather data for Nashua NH.  Forecast values begin September 1, 2009
Inches Rain Spray Date
- assumes that fungicide was applied before any rain fell on spray date
Protection End Date
for full-dose
Pristine,
Flint, Sovran, or Topsin M
(deadline for postinfection strobilurin or Topsin M)
Date flyspeck infections that started after end of protection could appear
(Left side = rough estimate of flyspeck show date for dense canopy trees if weather beyond forecast range is in top 20% of years for both temperature and wet hours.
x = show date is within forecast range.

Right side = rough estimate of flyspeck show date for small, open canopy, low-risk trees.)
0.01 Sat, August 1 Aug 22 (August 24) (Sep 23) October 5 (> Oct. 31)
0 Sun, August 2 Aug 23 (August 28) (Sep 26) October 11  
0 Mon, August 3 Aug 24 (August 29) (Sep 28) October 17  
0 Tue, August 4 Aug 25 (September 7) (Sep 29) October 21  
0 Wed, August 5 Aug 26 (September 7) (Sep 29) October 21  
0 Thu, August 6 Aug 27 (September 7) (Sep 29) October 21  
0 Fri, August 7 Aug 28 (September 8) (Sep 30) October 24  
0 Sat, August 8 Aug 29 (Oct 3) > Oct. 31  
0 Sun, August 9 Aug 29 (Oct 3)    
0 Mon, August 10 Aug 29 (Oct 3)    
0.14 Tue, August 11 Aug 29 (Oct 3)    
0 Wed, August 12 Aug 29 (Oct 3)    
0.11 Thu, August 13 Aug 29 (Oct 3)    
0 Fri, August 14 Aug 29   (Oct 3)    
0 Sat, August 15 Aug 29 (Oct 3)    
0 Sun, August 16 Aug 29 (Oct 3)    
0 Mon, August 17 Aug 29 (Oct 3)    
0 Tue, August 18 Aug 29 (Oct 3)    
0 Wed, August 19 Aug 29 (Oct 3)    
0 Thu, August 20 Aug 29 (Oct 3)    
0.47 Fri, August 21 Aug 29   (Oct 3)    
0.85 Sat, August 22 Aug 29 (Oct 3)    
0.39 Sun, August 23 Sep 9 (Oct 9)    
0.08 Mon, August 24 Sep 12 (Oct 16)    
0 Tue, August 25 Sep 12 (Oct 16)    
0 Wed, August 26 Sep 12 (Oct 16)    
0 Thu, August 27 Sep 12 (Oct 16)    
0.33 Fri, August 28 Sep 12   (Oct 16)    
1.57 Sat, August 29 Sep 15 (Oct 24)    
0 Sun, August 30 Sep 20 (> Oct. 31)    
0 Mon, August 31 Sep 21      
0 Tue, September 1 Sep 22      
0 Wed, September 2 Sep 23      
0 Thu, September 3 Sep 24      
0 Fri, September 4 Sep 25        
0 Sat, September 5 Sep 26      
0 Sun, September 6 Sep 27      
0 Mon, September 7 Sep 28      
Tue, September 8 Sep 28      
Wed, September 9 Sep 29      
Thu, September 10 Sep 30      
  Fri, September 11 Oct 1        
Sat, September 12 Oct 2      
Sun, September 13 Oct 3      
Mon, September 14 Oct 4      
Tue, September 15 Oct 5